May 14, 2002 — OK, so maybe lightsabers couldn’t work the way they seem to work for Obi-Wan Kenobi ... maybe those landspeeders rely on a technology that’s on the very edge of believability ... and the starfighters certainly wouldn’t make zooming noises in space. But scientists say there’s still a lot to be learned from the “Star Wars” sagas, even if the science isn’t quite right.

Even among science-fiction stories, the “Star Wars” movies are something of a breed apart. Instead of attempting to foretell our future in space, the tale is set “long ago, in a galaxy far away.” And the scientific marvels of that long-ago age, such as faster-than-light travel and synthetic space gravity, are employed primarily to facilitate a ripping good yarn.

For example, director George Lucas patterned the space chases and races after dogfights in World War II epics, motorcycle chases and chariot races. As a result, spaceship engines scream — even though there is no medium to transmit sound in the vacuum of space. The winged fighters bank and pirouette in space just as they would in Earth’s atmosphere. Weightless hovercraft swoop a couple of feet off the ground as if they were wheeled vehicles. And passengers aboard starships don’t have to trouble themselves over the effects of zero-gravity.

“The science is there to give the movie verisimilitude and to allow them to get around things,” says physicist Lawrence Krauss, who wrote “The Physics of ‘Star Trek’” and other books explaining the science within science fiction.

But strangely enough, there are some things that seem, well, less unbelievable now than they did in 1977 when the first “Star Wars” movie came out, says Jeanne Cavelos, an astronomer and author who wrote “The Science of ‘Star Wars.’”

“Science has caught up with George Lucas, and a lot of the things we believed were entirely fantastical in 1977 now seem compatible with our view of the universe,” she says.

Getting around
Making the jump to lightspeed might seem to violate the cosmic speed limit set by Einstein’s theories. Nevertheless, researchers are investigating ways to get around the law — or, as NASA’s Marc Millis puts it, “circumventing the light speed barrier by manipulating space-time.”

The Millennium Falcon uses faster-than-light speeds to jet around the galaxy - and has artificial gravity to boot.

As the lead researcher for the space agency’s Breakthrough Propulsion Physics Program, Millis focuses on far-out questions such as how to propel spacecraft without rocket propellant, whether vacuum energy or negative energy can be put to use, and whether quantum physics can get you from point A to point B without having to travel in between.

NASA puts hundreds of thousands of dollars into breakthrough research along these lines.

The NASA-funded research focuses on shorter-term issues as well as the big questions, Millis says. “It’s so early into the stage of things that we have to proceed cautiously, in an incremental fashion,” he says.

He declines to discuss specific proposals, but cites as a general example a phenomenon known as the Podkletnov Effect, which some believe demonstrates that objects can be shielded from gravity.

That particular technology would come in handy for the hovering landspeeders of “Star Wars.” But Krauss points out that all these science-fiction propulsion technologies — whether gravity-shielding, or magnetic levitation, or ultrafast space travel — would require prodigious amounts of energy, even if they were physically possible.

“The real limitation to traveling in space will be limited resources,” he says.

Choose your weapon
Perhaps the best-known item in the “Star Wars” hardware store is the lightsaber, wielded by Jedi Knights as well as their evil Sith rivals. In “Phantom Menace,” for example, the evil Darth Maul thrusts and parries with a double-bladed lightsaber.

The blade is no mere laser beam: If it were, one lightsaber could pass through another, and the blade’s “tip” would flash out right through the hull of the Millennium Falcon.

“Light has this nasty habit of always traveling at the speed of light,” Krauss observes. “You can’t contain it in empty space unless there’s some sort of medium there.”

Cavelos says the lightsaber effect could be duplicated by containing a superhot plasma within a magnetic field in the form of a figure-8. In the lightsaber’s case, the figure-8 would have to be so tall and narrow that it appeared to be a straight blade. This would represent an exaggerated variation of the “stellarator” concept for a nuclear fusion containment device.

Once again, the energy issue rears its head: Could you really fit the power source and all the equipment for a fusion reactor into a foot-long hilt?

Laser weapons such as the Death Star’s planet-blaster aren’t totally the stuff of science fiction, however: On a far smaller scale, the U.S. military is testing laser weapons that could be used against orbiting satellites or incoming spacecraft. China is reportedly testing its own anti-satellite laser system.

Denizens of space
When the first “Star Wars” was made, scientists assumed that planetary systems were extremely rare in the universe. In just the past few years, mainstream scientific opinion has swung around to the view that planets are much more common, and that life could well exist elsewhere in the universe.

Like humans, the alien Yoda has four limbs and two eyes, a nose and a mouth - which would seem to be a highly unlikely coincidence.

Among the candidates are moons revolving around gas giants, such as the fictional moons of Yavin or Endor — or real-life moons of Jupiter.

However, even if the universe is laden with life, it’s almost certain that the various species wouldn’t commune as they do in “Star Wars.”

“They’re all obviously pretty much on the same level, and they at least get along well enough that they could share a cantina,” observes astronomer Seth Shostak of the SETI Institute, who addresses the subject of alien life in his book “Sharing the Universe.”

“But that’s nonsense, you see, because the universe is about 15 billion years old, and the chances that two civilizations could have ever arisen within a million years of each other is not very high,” he says.

Of course, intelligent aliens need not look anything like humans — or even like lizards, Wookiees, worms or any Earth-centric conceptions we might have. In fact, Shostak says the first intelligent life forms to meet in space would probably have more in common with C-3PO and R2-D2: They’d likely be mechanical emissaries, sent out on missions that could continue long after their creators have decayed to dust.

“The cantina might more realistically be frequented by machines on a break than these squishy aliens,” Shostak says.

So what?In a sense, however, such scientific quibbles are little more than “technical nitpicking,” Shostak says. After all, it’s only science fiction. ... Or is it?

“The best thing about science fiction is that it’s inspirational,” Millis says. “It gives you a visual cue of what you could achieve with all these breakthroughs. ... What they are not good for is being research guides.”

In retrospect, Shostak recalls that the science-fiction films of his youth were far more ludicrous than “Star Wars.”

“What they did was, they reached me on an emotional level, and in the end I studied physics and astronomy because of these films,” he said. “You may say they were all wrong, but that isn’t the point. It’s the excitement that they created. ... Scientists aren’t born with lab coats and clipboards.”

Eventually, young “Star Wars” fans may find themselves sucked into a bizarre realm where creatures live around undersea volcanoes, where fusion reactions can take place on a table top, where planets can be detected around double-star systems — in short, the real world.

“I’m convinced that the real world is far more interesting and exotic than anything science-fiction writers could come up with,” Krauss says. “Truth really is stranger than fiction.”

This is an edited version of a report that first appeared in May 1999.